Artificial Sweeteners (Sugar Substitutes)

A sugar substitute is a food additive that duplicates the effect of sugar in taste, but usually has less food energy. Some sugar substitutes are natural and some are synthetic. Those that are not natural are, in general, referred to as artificial sweeteners.

An important class of sugar substitutes are known as high-intensity sweeteners. These are compounds with sweetness that is many times that of sucrose, common table sugar. As a result, much less sweetener is required, and energy contribution often negligible. The sensation of sweetness caused by these compounds (the "sweetness profile") is sometimes notably different from sucrose, so they are often used in complex mixtures that achieve the most natural sweet sensation.

If the sucrose (or other sugar) replaced has contributed to the texture of the product, then a bulking agent is often also needed. This may be seen in soft drinks labeled as "diet" or "light," which contain artificial sweeteners and often have notably different mouthfeel, or in table sugar replacements that mix maltodextrins with an intense sweetener to achieve satisfactory texture sensation.

In the United States, six intensely-sweet sugar substitutes have been approved for use. They are saccharin, aspartame, sucralose, neotame, acesulfame potassium, and stevia. There is some ongoing controversy over whether artificial sweetener usage poses health risks. The US Food and Drug Administration regulates artificial sweeteners as food additives. Food Additives must be approved by the FDA, which publishes a Generally Recognized as Safe (GRAS) list of additives. To date, the FDA has not been presented with scientific information that would support a change in conclusions about the safety of the six approved artificial sweeteners. The safe conclusions are based on a detailed review of a large body of information, including hundreds of toxicological and clinical studies.

There is also an herbal supplement, stevia, used as a sweetener. Controversy surrounds lack of research on stevia's safety and there is a battle over its approval as a sugar substitute.

The majority of sugar substitutes approved for food use are artificially-synthesized compounds. However, some bulk natural sugar substitutes are known, including sorbitol and xylitol, which are found in berries, fruit, vegetables, and mushrooms. It is not commercially viable to extract these products from fruits and vegetables, so they are produced by catalytic hydrogenation of the appropriate reducing sugar. For example, xylose is converted to xylitol, lactose to lactitol, and glucose to sorbitol. Still other natural substitutes are known, but are yet to gain official approval for food use.

Some non-sugar sweeteners are polyols, also known as "sugar alcohols." These are, in general, less sweet than sucrose, but have similar bulk properties and can be used in a wide range of food products. Sometimes the sweetness profile is 'fine-tuned' by mixing high-intensity sweeteners. As with all food products, the development of a formulation to replace sucrose is a complex proprietary process.

Controversy over health

A 2005 study by the University of Texas Health Science Center at San Antonio showed that increased weight gain and obesity was associated with increased use of diet soda in a population based study. The study did not establish whether increased weight leads to increased consumption of diet drinks or whether consumption of diet drinks could have an effect on weight gain.

Animal studies have indicated that artificial sweeteners can cause body weight gain. A sweet taste induces an insulin response, which causes blood sugar to be stored in tissues (including fat), but because blood sugar does not increase with artificial sugars, there is hypoglycemia and increased food intake the next time there is a meal. After a while, rats given sweeteners have steadily increased calorie intake, increased body weight, and increased adiposity (fatness). Furthermore, the natural responses to eating sugary foods (eating less at the next meal and using some of the extra calories to warm the body after the sugary meal) are gradually lost.

Cyclamate

In the United States, the U.S. Food and Drug Administration (FDA) banned the sale of cyclamate in 1970 after lab tests in rats involving a 10:1 mixture of cyclamate and saccharin indicated that large amounts of cyclamates causes bladder cancer, a disease to which rats are particularly susceptible. The findings of these studies have been challenged and some companies are petitioning to have cyclamates reapproved. Cyclamates are still used as sweeteners in many parts of the world, and are used with official approval in over 55 countries.

Saccharin

Aside from Sugar of lead, Saccharin was the first artificial sweetener and was originally synthesized in 1879 by Remsen and Fahlberg. Its sweet taste was discovered by accident. It had been created in an experiment with toluene derivatives. A process for the creation of saccharin from phthalic anhydride was developed in 1950, and, currently, saccharin is created by this process as well as the original process by which it was discovered. It is 300 to 500 times as sweet as sugar (sucrose) and is often used to improve the taste of toothpastes, dietary foods, and dietary beverages. The bitter aftertaste of saccharin is often minimized by blending it with other sweeteners.

Fear about saccharin increased when a 1960 study showed that high levels of saccharin may cause bladder cancer in laboratory rats. In 1977, Canada banned saccharin due to the animal research. In the United States, the FDA considered banning saccharin in 1977, but Congress stepped in and placed a moratorium on such a ban. The moratorium required a warning label and also mandated further study of saccharin safety.

Subsequently, it was discovered that saccharin causes cancer in male rats by a mechanism not found in humans. At high doses, saccharin causes a precipitate to form in rat urine. This precipitate damages the cells lining the bladder ("urinary bladder urothelial cytotoxicity") and a tumor forms when the cells regenerate ("regenerative hyperplasia"). According to the International Agency for Research on Cancer, part of the World Health Organization, "Saccharin and its salts was downgraded from Group 2B, possibly carcinogenic to humans, to Group 3, not classifiable as to carcinogenicity to humans, despite sufficient evidence of carcinogenicity to animals, because it is carcinogenic by a non-DNA-reactive mechanism that is not relevant to humans because of critical interspecies differences in urine composition."

In 2001, the United States repealed the warning label requirement, while the threat of an FDA ban had already been lifted in 1991. Most other countries also permit saccharin but restrict the levels of use, while other countries have outright banned it.

Aspartame

Aspartame was discovered in 1965 by James M. Schlatter at the G.D. Searle company (later purchased by Monsanto). He was working on an anti-ulcer drug and spilled some aspartame on his hand by accident. When he licked his finger, he noticed that it had a sweet taste. It is an odorless, white crystalline powder that is derived from the two amino acids aspartic acid and phenylalanine. It is about 200 times as sweet as sugar and can be used as a tabletop sweetener or in frozen desserts, gelatins, beverages, and chewing gum. Its chemical name is L-alpha-aspartyl-L-phenylalanine methyl ester and its chemical formula is C14H18N2O5. Though it has no bitter aftertaste as does saccharin, its drawback is that it might not taste exactly like sugar because it reacts with other food flavors. When eaten, aspartame is metabolized into its original amino acids and has a relatively low food energy.

Since the FDA approved aspartame for consumption, some researchers have suggested that a rise in brain tumor rates in the United States may be at least partially related to the increasing availability and consumption of aspartame. Some research, often supported by companies producing artificial sweeteners, has failed to find any link between aspartame and cancer or other health problems. Recent research showed a clear link between this substance and cancer; leading some experts to call for the FDA to pull aspartame from the market. This research has led the Center for Science in the Public Interest to classify aspartame as a substance to be avoided in its Chemical Cuisine Directory. However, the EFSA's press release about the study,[14] published on 5 May 2006, concluded that the increased incidence of lymphomas/leukaemias reported in treated rats was unrelated to aspartame, the kidney tumors found at high doses of aspartame were not relevant to humans, and that based on all available scientific evidence to date, there was no reason to revise the previously established Acceptable Daily Intake levels for aspartame.

Several European Union countries approved aspartame in the 1980s, with EU-wide approval in 1994. The European Commission Scientific Committee on Food reviewed subsequent safety studies and reaffirmed the approval in 2002. The European Food Safety Authority reported in 2006 that the previously established Adequate Daily Intake was appropriate, after reviewing yet another set of studies.

It has also been investigated and approved by the Joint Expert Committee on Food Additives of the United Nations Food and Agricultural Organization and World Health Organization.

Sucralose

Sucralose is a chlorinated sugar that is about 600 times as sweet as sugar. It is produced from sucrose when three chlorine atoms replace three hydroxyl groups. It is used in beverages, frozen desserts, chewing gum, baked goods, and other foods. Unlike other artificial sweeteners, it is stable when heated and can therefore be used in baked and fried goods. Sucralose is minimally absorbed by the body and most of it passes out of the body unchanged. The FDA approved sucralose in 1998.

Most of the controversy surrounding Splenda, a sucralose sweetener, is focused not on safety, but on its marketing. It has been marketed with the slogan, "Splenda is made from sugar, so it tastes like sugar." Sucralose is a chlorinated sugar prepared from either sucrose or raffinose. With either base sugar, processing replaces three oxygen-hydrogen groups in the sugar molecule with three chlorine atoms.

The "Truth About Splenda" website was created in 2005 by The Sugar Association, an organization representing sugar beet and sugar cane farmers in the United States, in order to provide its view of sucralose. In December 2004, five separate false-advertising claims were filed by the Sugar Association against Splenda manufacturers Merisant and McNeil Nutritionals for claims made about Splenda related to the slogan, "Made from sugar, so it tastes like sugar". French courts ordered the slogan to no longer be used in France, while in the U.S. the case came to an undisclosed settlement during the trial.

Safety concerns pertaining to sucralose revolve around the fact that it belongs to a class of chemicals called organochlorides, some types of which are toxic or carcinogenic; however, the presence of chlorine in an organic compound does not in any way ensure toxicity. The way sucralose is metabolized may suggest a reduced risk of toxicity. For example, sucralose is extremely insoluble in fat and thus does not accumulate in fat as do some other organochlorides; sucralose also does not break down and will dechlorinate only under conditions that are not found during regular digestion ( i.e. heavy heat applied to the powder form of the molecule).

Lead acetate

Lead acetate (sometimes called sugar of lead) is an artificial sugar substitute made from lead that is of historical interest because of its widespread use in the past, such as by ancient Romans. The use of lead acetate as a sweetener eventually produced lead poisoning in any individual ingesting it habitually. Lead acetate was abandoned as a food additive throughout most of the world after the high toxicity of lead compounds became apparent.